The series of halogenated n-alkanes contains compounds that do and do not produce anesthesia. We propose to synthesize a number of compounds that lie near the border of the anesthetic and nonanesthetic domains. The synthesis of the following compounds will be investigated, either by existing methods or by methods we will develop: (1) polyfluorinated n- alkanes containing hydrogen and/or chlorine atoms, or bromine atoms at one or both of the terminal carbons; (2) dibromoperfluorocyclobutane and cyclopentane; (3) polyfluorinated methyl ethyl ethers containing hydrogen and/or chlorine atoms, or bromine atoms on one or both of the terminal carbons; (4) polyfluorinated alcohols. Over the period of the program project we will prepare 24 compounds according to the directives of the Core and supply these of all the investigators. We will also address resynthesis of samples and provide the flexibility to respond to any shifts in focus as dictated by the Core. Our participation in this Program Project will add another dimension to the project. We will contribute the viewpoint of the fluorine chemist. This might be particularly helpful in the discussions of the group concerning the implications of the physical properties of these compounds and the factors that distinguish anesthetic from nonanesthetic compounds. The significance of our contribution apart from providing the needed compounds, some of which we have made previously, lie in the improvements we will contribute to the known methods of synthesis and to the scale-up technology required to produce the compounds on a medium scale.